Top Cowl and Firewall work

 The Silicone/Fiberglass baffle seal was received from Aircraft spruce and cut to the desired shape.  We chose 2" of overlap as our starting point but later trimmed it down to about 1", which worked much better at contouring to the boot cowl shape.  The backer bracket was used to locate the holes and the holes where punched in the silicone with a hand bunch.  Currently the baffle seal is cleco'd in place awaiting rivets.

The firewall was finally riveted to the fuselage, replacing the clecos that had been holding it in place.

Baffle Seal Cleco'd in Place

We decided we wanted an access door in the top cowl so that we could quickly check the oil level in the oil tank.   Michael had some left-over Hartwell latches from his previous project that fit the bill perfectly. We also ordered a hidden hinge from Aircraft Spruce.  The access door needed to be large enough  to reach down and remove the oil tank lid.  Once that was determined, an extra lip was needed for the door to close against.  We chose a 1/2" lip.  The access door was marked on the top cowl and cut out with a Dremel tool.  A new door was fashioned out of 0.040" aluminum and it was coaxed into shape since the top cowl is curved.  To create the needed lip for the door to seal against we needed to use fiberglass/epoxy.  The original piece of fiberglass that was cutout of the top cowl was coated with packing tape, which epoxy doesn't stick to. It was taped back into its position on the top side.  Some modeling clay was put in the cut gap to create a smooth inside surface.  Four layers of fiberglass was layed up and allowed to dry.  Once cured, the old door was removed.  The 1/2" lip was drawn and the excess fiberglass was cutout with a Dremel.  The cutout for the Hartwell latches with made on poster board and transferred to the metal access door.  The holes were cutout and each latch were installed with 4 solid rivets.  Next the hinge location was set. The holes were drill in the cowl and access door and then riveted in place  with solid rivets.

Oil Access Door with Fiberglass Lip

Oil Access Door with Latches and Hinge Installed

The throttle cable pass-thru on the firewall was installed.  We bought a "eyeball" firewall pass-thru from Aircraft Spruce that worked out nicely.  Once tightened, it provided a nice sealed port for the throttle.

Hours: 20

Cabin Side of Throttle Cable Eyeball Port

Engine Side of Throttle Cable Eyeball Port